Abstract

PURPOSE: To determine the efficacy of early extracorporeal shockwave lithotripsy (e-ESWL) in colic patients with ureteral stones and the patient criteria for the most effective e-ESWL. MATERIALS AND METHODS: For 335 patients who were received ESWL due to ureteral stone, were divide in two groups: e-ESWL and d-ESWL by the critical cut-off point. we performed the sensitivity and specificity cut-off analyses to identified the critical cut off point. To assess the difference in the factors affecting ESWL success, univariate and multivariate logistic analyses were implemented with using variables: ESWL success; age; gender; BMI; comorbidity; serum creatinine; stone size; stone location; stone laterality; Hounsfield unit (HU); presence of hydronephrosis; and presence of tissue rim. The subgroup analysis for the screened variables was conducted. RESULTS: Define optimal e-ESWL to occur within a 24-hour critical cut-off time. Multivariate regression analysis concluded with screened variables: age, stone size, stone location, and HU, that ESWL success was 1.85-fold higher in the e-ESWL patient group. The subgroup analyses the following conditions: ?65 years old by 1.784-fold; ?10 mm stone size by 1.866-fold; mid to distal stone location by 2.234-fold; and ?815 HU by 2.130-fold. When all the conditions were met, the e-ESWL success was 3.22-fold higher. CONCLUSIONS: In case of colic due to ureteral stones, the patient is recommended to receive a lithotripsy within the first 24 hours. E-ESWL is recommended especially in patients who are ?65 years, or with a ureteral stone HU ?815, sized ?10 mm, or in a mid to distal location.

Urol J. 2018 Oct 8. doi: 10.22037/uj.v0i0.4537. [Epub ahead of print]

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Comments
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This report on SWL of ureteral stones is interesting and the outcome carefully analysed.
All treatments were made with the Modulith SLX-F2 lithotripter. Stratification was made in early and deferred treatment. For this purpose the time limit was set to 24h; a time interval that was obtained from ROC analysis.

All treatments were carried out in a standardized way with 3000 shock waves administered at a rate of 1.5 Hz. It is mentioned that the same power was applied with each shock wave, but the energy level cannot be found in the text.

Another point that deserves attention is the analgesic regimen. The authors report that the patients received either 30 mg of diclofenac i.m. or 50 mg of pethidin i.v. These two pharmacologic alternatives are not comparable and it is possible that the relatively low mean stone free rate of 74% after in average 1.95±1.2 SWL-sessions can be explained by insufficient pain control. It is not stated how many of the patients that were treated with each one of these two analgesics. It is surprising that none of the patients required additional pain treatment!

A distinction was made between proximal and mid/distal ureteral stones, but it is not mentioned how patients with mid-ureteral stones were treated.

The comment in the Discussion of this article that distal ureteral stones are better treated with URS is difficult to understand. In my own experience the greatest stone-free rate with one SWL session (and with the same lithotripter) was recorded for distal ureteral stones [1].

The results are in line with those in previous reports and support the idea that early SWL is superior to deferred SWL. In a meta-analysis published in 2012 [2] stone-free rates obtained from seven studies ranged between 72 and 86%. All these patients were given emergency treatment with the rational to avoid the negative effects of oedema formation around the stone. Stone impaction on this basis was considered to occur within 24-48h after the initial colic episode. Although the authors of the meta-analysis [2] recommended further randomized studies; so far no such studies have been published.

The lesson learnt: Always attempt to treat ureteral stones within 24h after diagnosis.

This report on SWL of ureteral stones is interesting and the outcome carefully analysed.
All treatments were made with the Modulith SLX-F2 lithotripter. Stratification was made in early and deferred treatment. For this purpose the time limit was set to 24h; a time interval that was obtained from ROC analysis.
All treatments were carried out in a standardized way with 3000 shock waves administered at a rate of 1.5 Hz. It is mentioned that the same power was applied with each shock wave, but the energy level cannot be found in the text.
Another point that deserves attention is the analgesic regimen. The authors report that the patients received either 30 mg of diclofenac i.m. or 50 mg of pethidin i.v. These two pharmacologic alternatives are not comparable and it is possible that the relatively low mean stone free rate of 74% after in average 1.95±1.2 SWL-sessions can be explained by insufficient pain control. It is not stated how many of the patients that were treated with each one of these two analgesics. It is surprising that none of the patients required additional pain treatment!
A distinction was made between proximal and mid/distal ureteral stones, but it is not mentioned how patients with mid-ureteral stones were treated.
The comment in the Discussion of this article that distal ureteral stones are better treated with URS is difficult to understand. In my own experience the greatest stone-free rate with one SWL session (and with the same lithotripter) was recorded for distal ureteral stones [1].
The results are in line with those in previous reports and support the idea that early SWL is superior to deferred SWL. In a meta-analysis published in 2012 [2] stone-free rates obtained from seven studies ranged between 72 and 86%. All these patients were given emergency treatment with the rational to avoid the negative effects of oedema formation around the stone. Stone impaction on this basis was considered to occur within 24-48h after the initial colic episode. Although the authors of the meta-analysis [2] recommended further randomized studies; so far no such studies have been published.
The lesson learnt: Always attempt to treat ureteral stones within 24h after diagnosis.
References:
1. Tiselius HG. How efficient is extracorporeal shockwave lithotripsy with modern lithotripters for removal of ureteral stones?
J Endourol. 2008;22(2):249-255.
2. Picozzi SC, Ricci C, Gaeta M, Casellato S, Stubinski R, Ratti D, Bozzini G, Carmignani L Urgent shock wave lithotripsy as first-line treatment for ureteral stones: a meta-analysis of 570 patients.Urol Res. 2012; 40(6):725-731.